RESUMO
Vector-borne diseases are a leading cause of death worldwide and pose a substantial unmet medical need. Pathogens binding to host extracellular proteins (the "exoproteome") represents a crucial interface in the etiology of vector-borne disease. Here, we used bacterial selection to elucidate host-microbe interactions in high throughput (BASEHIT)-a technique enabling interrogation of microbial interactions with 3,324 human exoproteins-to profile the interactomes of 82 human-pathogen samples, including 30 strains of arthropod-borne pathogens and 8 strains of related non-vector-borne pathogens. The resulting atlas revealed 1,303 putative interactions, including hundreds of pairings with potential roles in pathogenesis, including cell invasion, tissue colonization, immune evasion, and host sensing. Subsequent functional investigations uncovered that Lyme disease spirochetes recognize epidermal growth factor as an environmental cue of transcriptional regulation and that conserved interactions between intracellular pathogens and thioredoxins facilitate cell invasion. In summary, this interactome atlas provides molecular-level insights into microbial pathogenesis and reveals potential host-directed targets for next-generation therapeutics.
Assuntos
Interações Hospedeiro-Patógeno , Humanos , Animais , Doença de Lyme/microbiologia , Doenças Transmitidas por Vetores , Interações entre Hospedeiro e Microrganismos , Borrelia burgdorferi/patogenicidade , Borrelia burgdorferi/metabolismoRESUMO
The emerging SARS-CoV-2 variants of concern (VOCs) threaten the effectiveness of current COVID-19 vaccines administered intramuscularly and designed to only target the spike protein. There is a pressing need to develop next-generation vaccine strategies for broader and long-lasting protection. Using adenoviral vectors (Ad) of human and chimpanzee origin, we evaluated Ad-vectored trivalent COVID-19 vaccines expressing spike-1, nucleocapsid, and RdRp antigens in murine models. We show that single-dose intranasal immunization, particularly with chimpanzee Ad-vectored vaccine, is superior to intramuscular immunization in induction of the tripartite protective immunity consisting of local and systemic antibody responses, mucosal tissue-resident memory T cells and mucosal trained innate immunity. We further show that intranasal immunization provides protection against both the ancestral SARS-CoV-2 and two VOC, B.1.1.7 and B.1.351. Our findings indicate that respiratory mucosal delivery of Ad-vectored multivalent vaccine represents an effective next-generation COVID-19 vaccine strategy to induce all-around mucosal immunity against current and future VOC.
Assuntos
Vacinas contra COVID-19/administração & dosagem , COVID-19/prevenção & controle , Imunidade nas Mucosas , Administração Intranasal , Animais , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Linfócitos B/imunologia , Linfócitos B/metabolismo , COVID-19/virologia , Vacinas contra COVID-19/imunologia , Citocinas/sangue , Vetores Genéticos/genética , Vetores Genéticos/imunologia , Vetores Genéticos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Testes de Neutralização , Nucleocapsídeo/genética , Nucleocapsídeo/imunologia , Nucleocapsídeo/metabolismo , Pan troglodytes , SARS-CoV-2/genética , SARS-CoV-2/imunologia , SARS-CoV-2/isolamento & purificação , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Linfócitos T/imunologia , Linfócitos T/metabolismoRESUMO
Pediatric SARS-CoV-2 vaccines are needed that elicit immunity directly in the airways as well as systemically. Building on pediatric parainfluenza virus vaccines in clinical development, we generated a live-attenuated parainfluenza-virus-vectored vaccine candidate expressing SARS-CoV-2 prefusion-stabilized spike (S) protein (B/HPIV3/S-6P) and evaluated its immunogenicity and protective efficacy in rhesus macaques. A single intranasal/intratracheal dose of B/HPIV3/S-6P induced strong S-specific airway mucosal immunoglobulin A (IgA) and IgG responses. High levels of S-specific antibodies were also induced in serum, which efficiently neutralized SARS-CoV-2 variants of concern of alpha, beta, and delta lineages, while their ability to neutralize Omicron sub-lineages was lower. Furthermore, B/HPIV3/S-6P induced robust systemic and pulmonary S-specific CD4+ and CD8+ T cell responses, including tissue-resident memory cells in the lungs. Following challenge, SARS-CoV-2 replication was undetectable in airways and lung tissues of immunized macaques. B/HPIV3/S-6P will be evaluated clinically as pediatric intranasal SARS-CoV-2/parainfluenza virus type 3 vaccine.
Assuntos
Vacinas contra COVID-19 , COVID-19 , Animais , Humanos , Anticorpos Neutralizantes , Anticorpos Antivirais , Macaca mulatta , COVID-19/prevenção & controle , SARS-CoV-2/genéticaRESUMO
Single-cell (sc)RNA-seq, together with RNA velocity and metabolic labeling, reveals cellular states and transitions at unprecedented resolution. Fully exploiting these data, however, requires kinetic models capable of unveiling governing regulatory functions. Here, we introduce an analytical framework dynamo (https://github.com/aristoteleo/dynamo-release), which infers absolute RNA velocity, reconstructs continuous vector fields that predict cell fates, employs differential geometry to extract underlying regulations, and ultimately predicts optimal reprogramming paths and perturbation outcomes. We highlight dynamo's power to overcome fundamental limitations of conventional splicing-based RNA velocity analyses to enable accurate velocity estimations on a metabolically labeled human hematopoiesis scRNA-seq dataset. Furthermore, differential geometry analyses reveal mechanisms driving early megakaryocyte appearance and elucidate asymmetrical regulation within the PU.1-GATA1 circuit. Leveraging the least-action-path method, dynamo accurately predicts drivers of numerous hematopoietic transitions. Finally, in silico perturbations predict cell-fate diversions induced by gene perturbations. Dynamo, thus, represents an important step in advancing quantitative and predictive theories of cell-state transitions.
Assuntos
Análise de Célula Única , Transcriptoma/genética , Algoritmos , Feminino , Regulação da Expressão Gênica , Células HL-60 , Hematopoese/genética , Células-Tronco Hematopoéticas/metabolismo , Humanos , Cinética , Modelos Biológicos , RNA Mensageiro/metabolismo , Coloração e RotulagemRESUMO
Ticks transmit a diverse array of microbes to vertebrate hosts, including human pathogens, which has led to a human-centric focus in this vector system. Far less is known about pathogens of ticks themselves. Here, we discover that a toxin in blacklegged ticks (Ixodes scapularis) horizontally acquired from bacteria-called domesticated amidase effector 2 (dae2)-has evolved to kill mammalian skin microbes with remarkable efficiency. Secreted into the saliva and gut of ticks, Dae2 limits skin-associated staphylococci in ticks while feeding. In contrast, Dae2 has no intrinsic ability to kill Borrelia burgdorferi, the tick-borne Lyme disease bacterial pathogen. These findings suggest ticks resist their own pathogens while tolerating symbionts. Thus, just as tick symbionts can be pathogenic to humans, mammalian commensals can be harmful to ticks. Our study underscores how virulence is context-dependent and bolsters the idea that "pathogen" is a status and not an identity.
Assuntos
Bactérias/metabolismo , Fatores Imunológicos/metabolismo , Ixodes/fisiologia , Pele/microbiologia , Simbiose , Animais , Antibacterianos/farmacologia , Biocatálise , Parede Celular/metabolismo , Comportamento Alimentar , Feminino , Trato Gastrointestinal/metabolismo , Interações Hospedeiro-Patógeno , Camundongos , Modelos Moleculares , Peptidoglicano/metabolismo , Filogenia , Saliva/metabolismo , Glândulas Salivares/metabolismo , Staphylococcus epidermidis/fisiologia , Homologia Estrutural de Proteína , Especificidade por Substrato , Regulação para CimaRESUMO
Among arthropod vectors, ticks transmit the most diverse human and animal pathogens, leading to an increasing number of new challenges worldwide. Here we sequenced and assembled high-quality genomes of six ixodid tick species and further resequenced 678 tick specimens to understand three key aspects of ticks: genetic diversity, population structure, and pathogen distribution. We explored the genetic basis common to ticks, including heme and hemoglobin digestion, iron metabolism, and reactive oxygen species, and unveiled for the first time that genetic structure and pathogen composition in different tick species are mainly shaped by ecological and geographic factors. We further identified species-specific determinants associated with different host ranges, life cycles, and distributions. The findings of this study are an invaluable resource for research and control of ticks and tick-borne diseases.
Assuntos
Variação Genética/genética , Doenças Transmitidas por Carrapatos/microbiologia , Carrapatos/genética , Animais , Linhagem Celular , Vetores de Doenças , Especificidade de Hospedeiro/genéticaRESUMO
Aided by extensive spike protein mutation, the SARS-CoV-2 Omicron variant overtook the previously dominant Delta variant. Spike conformation plays an essential role in SARS-CoV-2 evolution via changes in receptor-binding domain (RBD) and neutralizing antibody epitope presentation, affecting virus transmissibility and immune evasion. Here, we determine cryo-EM structures of the Omicron and Delta spikes to understand the conformational impacts of mutations in each. The Omicron spike structure revealed an unusually tightly packed RBD organization with long range impacts that were not observed in the Delta spike. Binding and crystallography revealed increased flexibility at the functionally critical fusion peptide site in the Omicron spike. These results reveal a highly evolved Omicron spike architecture with possible impacts on its high levels of immune evasion and transmissibility.
Assuntos
COVID-19 , SARS-CoV-2 , Enzima de Conversão de Angiotensina 2 , Humanos , Mutação , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/químicaRESUMO
Long-term delivery of anti-HIV monoclonal antibodies (mAbs) using adeno-associated virus (AAV) vectors holds promise for the prevention and treatment of HIV infection. We describe a therapy trial in which four rhesus monkeys were infected with SHIV-AD8 for 86 weeks before receiving the AAV-encoded mAbs 3BNC117, 10-1074, and 10E8. Although anti-drug antibody (ADA) responses restricted mAb delivery, one monkey successfully maintained 50-150 µg/mL of 3BNC117 and 10-1074 for over 2 years. Delivery of these two mAbs to this monkey resulted in an abrupt decline in plasma viremia, which remained undetectable for 38 successive measurements over 3 years. We generated two more examples of virologic suppression using AAV delivery of a cocktail of four mAbs in a 12-monkey study. Our results provide proof of concept for AAV-delivered mAbs to produce a "functional cure." However, they also serve as a warning that ADAs may be a problem for practical application of this approach in humans.
Assuntos
Anticorpos Monoclonais/imunologia , Dependovirus/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Animais , Anticorpos Monoclonais Humanizados , Anticorpos Neutralizantes/imunologia , Anticorpos Amplamente Neutralizantes , Linhagem Celular , Células HEK293 , Anticorpos Anti-HIV/imunologia , Humanos , Macaca mulatta , Viremia/imunologiaRESUMO
Wolbachia is an endosymbiotic Alphaproteobacteria that can suppress insect-borne diseases through decreasing host virus transmission (population replacement) or through decreasing host population density (population suppression). We contrast natural Wolbachia infections in insect populations with Wolbachia transinfections in mosquitoes to gain insights into factors potentially affecting the long-term success of Wolbachia releases. Natural Wolbachia infections can spread rapidly, whereas the slow spread of transinfections is governed by deleterious effects on host fitness and demographic factors. Cytoplasmic incompatibility (CI) generated by Wolbachia is central to both population replacement and suppression programs, but CI in nature can be variable and evolve, as can Wolbachia fitness effects and virus blocking. Wolbachia spread is also influenced by environmental factors that decrease Wolbachia titer and reduce maternal Wolbachia transmission frequency. More information is needed on the interactions between Wolbachia and host nuclear/mitochondrial genomes, the interaction between invasion success and local ecological factors, and the long-term stability of Wolbachia-mediated virus blocking.
Assuntos
Controle de Doenças Transmissíveis/métodos , Interações Hospedeiro-Patógeno/fisiologia , Insetos Vetores/virologia , Wolbachia/fisiologia , Animais , Evolução Biológica , Citoplasma , Meio Ambiente , Aptidão Genética , Insetos Vetores/microbiologia , Insetos/microbiologia , Insetos/virologia , Mosquitos Vetores/microbiologia , Mosquitos Vetores/virologiaRESUMO
Female mosquitoes produce eggs in gonadotrophic cycles that are divided between a previtellogenic and vitellogenic phase. Previtellogenic females consume water and sugar sources like nectar while also being attracted to hosts for blood feeding. Consumption of a blood meal activates the vitellogenic phase, which produces mature eggs and suppresses host attraction. In this study, we tested the hypothesis that neuropeptide Y-like hormones differentially modulate host attraction behavior in the mosquito Aedes aegypti. A series of experiments collectively indicated that enteroendocrine cells (EECs) in the posterior midgut produce and release neuropeptide F (NPF) into the hemolymph during the previtellogenic phase which stimulates attraction to humans and biting behavior. Consumption of a blood meal, which primarily consists of protein by dry weight, down-regulated NPF in EECs until mature eggs developed, which was associated with a decline in hemolymph titer. NPF depletion depended on protein digestion but was not associated with EEC loss. Other experiments showed that neurons in the terminal ganglion extend axons to the posterior midgut and produce RYamide, which showed evidence of increased secretion into circulation after a blood meal. Injection of RYamide-1 and -2 into previtellogenic females suppressed host attraction, while coinjection of RYamides with or without short NPF-2 also inhibited the host attraction activity of NPF. Overall, our results identify NPF and RYamide as gut-associated hormones in A. aegypti that link host attraction behavior to shifts in diet during sequential gonadotrophic cycles.
Assuntos
Aedes , Neuropeptídeos , Animais , Aedes/metabolismo , Aedes/fisiologia , Neuropeptídeos/metabolismo , Feminino , Comportamento Alimentar/fisiologia , Hemolinfa/metabolismo , Células Enteroendócrinas/metabolismo , Proteínas de Insetos/metabolismo , Humanos , Vitelogênese/fisiologiaRESUMO
Aedes aegypti mosquitoes are major vectors of dengue, chikungunya, and other arboviral diseases. Ae. aegypti's capacity to reproduce and to spread disease depends on the female mosquitoes' ability to obtain blood meals and find water-filled containers in which to lay eggs (oviposit). While humidity sensation (hygrosensation) has been implicated in these behaviors, the specific hygrosensory pathways involved have been unclear. Here, we establish the distinct molecular requirements and anatomical locations of Ae. aegypti Dry Cells and Moist Cells and examine their contributions to behavior. We show that Dry Cell and Moist Cell responses to humidity involve different ionotropic receptor (IR) family sensory receptors, with dry air-activated Dry Cells reliant upon the IR Ir40a, and humid air-activated Moist Cells upon Ir68a. Both classes of hygrosensors innervate multiple antennal sensilla, including sensilla ampullacea near the antennal base as well as two classes of coeloconic sensilla near the tip. Dry Cells and Moist Cells each support behaviors linked to mosquito reproduction but contribute differently: Ir40a-dependent Dry Cells act in parallel with Ir68a-dependent Moist Cells to promote blood feeding, while oviposition site seeking is driven specifically by Ir68a-dependent Moist Cells. Together these findings reveal the importance of distinct hygrosensory pathways in blood feeding and oviposition site seeking and suggest Ir40a-dependent Dry Cells and Ir68a-dependent Moist Cells as potential targets for vector control strategies.
Assuntos
Aedes , Comportamento Alimentar , Umidade , Mosquitos Vetores , Oviposição , Animais , Aedes/fisiologia , Oviposição/fisiologia , Feminino , Comportamento Alimentar/fisiologia , Mosquitos Vetores/fisiologia , Sensilas/fisiologia , Receptores Ionotrópicos de Glutamato/metabolismo , Antenas de Artrópodes/fisiologiaRESUMO
Malaria is a disease of global significance. Ongoing changes to the earth's climate, antimalarial resistance, insecticide resistance, and socioeconomic decline test the resilience of malaria prevention programs. Museum insect specimens present an untapped resource for studying vector-borne pathogens, spurring the question: Do historical mosquito collections contain Plasmodium DNA, and, if so, can museum specimens be used to reconstruct the historical epidemiology of malaria? In this Perspective, we explore molecular techniques practical to pathogen prospecting, which, more broadly, we define as the science of screening entomological museum specimens for human, animal, or plant pathogens. Historical DNA and pathogen prospecting provide a means of describing the coevolution of human, vector, and parasite, informing the development of insecticides, diagnostics, therapeutics, and vaccines.
Assuntos
Anopheles , Inseticidas , Malária , Animais , Humanos , Museus , Anopheles/genética , Mosquitos Vetores , Malária/epidemiologia , Malária/prevenção & controle , Resistência a Inseticidas , Inseticidas/farmacologia , DNA , Controle de MosquitosRESUMO
Wing dimorphism of insect vectors is a determining factor for viral long-distance dispersal and large-area epidemics. Although plant viruses affect the wing plasticity of insect vectors, the potential underlying molecular mechanisms have seldom been investigated. Here, we found that a planthopper-vectored rice virus, rice stripe virus (RSV), specifically induces a long-winged morph in male insects. The analysis of field populations demonstrated that the long-winged ratios of male insects are closely associated with RSV infection regardless of viral titers. A planthopper-specific and testis-highly expressed gene, Encounter, was fortuitously found to play a key role in the RSV-induced long-winged morph. Encounter resembles malate dehydrogenase in the sequence, but it does not have corresponding enzymatic activity. Encounter is upregulated to affect male wing dimorphism at early larval stages. Encounter is closely connected with the insulin/insulin-like growth factor signaling pathway as a downstream factor of Akt, of which the transcriptional level is activated in response to RSV infection, resulting in the elevated expression of Encounter. In addition, an RSV-derived small interfering RNA directly targets Encounter to enhance its expression. Our study reveals an unreported mechanism underlying the direct regulation by a plant virus of wing dimorphism in its insect vectors, providing the potential way for interrupting viral dispersal.
Assuntos
Epidemias , Vírus de Plantas , Infecções por Vírus Respiratório Sincicial , Tenuivirus , Masculino , Animais , Vírus de Plantas/genética , Tenuivirus/genética , Insetos Vetores , Peptídeos Semelhantes à InsulinaRESUMO
Malaria is caused by Plasmodium protozoa that are transmitted by anopheline mosquitoes. Plasmodium sporozoites are released with saliva when an infected female mosquito takes a blood meal on a vertebrate host. Sporozoites deposited into the skin must enter a blood vessel to start their journey towards the liver. After migration out of the mosquito, sporozoites are associated with, or in proximity to, many components of vector saliva in the skin. Recent work has elucidated how Anopheles saliva, and components of saliva, can influence host-pathogen interactions during the early stage of Plasmodium infection in the skin. Here, we discuss how components of Anopheles saliva can modulate local host responses and affect Plasmodium infectivity. We hypothesize that therapeutic strategies targeting mosquito salivary proteins can play a role in controlling malaria and other vector-borne diseases.
Assuntos
Anopheles , Malária , Humanos , Animais , Feminino , Anopheles/parasitologia , Anopheles/fisiologia , Saliva , Mosquitos Vetores/parasitologia , EsporozoítosRESUMO
Viruses have developed various strategies to ensure their survival and transmission. One intriguing strategy involves manipulating the behavior of infected arthropod vectors and hosts. Through intricate interactions, viruses can modify vector behavior, aiding in crossing barriers and improving transmission to new hosts. This manipulation may include altering vector feeding preferences, thus promoting virus transmission to susceptible individuals. In addition, viruses employ diverse dissemination methods, including cell-to-cell and intercellular transmission via extracellular vesicles. These strategies allow viruses to establish themselves in favorable environments, optimize replication, and increase the likelihood of spreading to other individuals. Understanding these complex viral strategies offers valuable insights into their biology, transmission dynamics, and potential interventions for controlling infections. Unraveling interactions between viruses, hosts, and vectors enables the development of targeted approaches to effectively mitigate viral diseases and prevent transmission.
Assuntos
Viroses , Animais , Humanos , Viroses/transmissão , Viroses/prevenção & controle , Viroses/virologia , Vírus , Vetores Artrópodes/virologia , Interações Hospedeiro-Patógeno , Vesículas Extracelulares/virologia , Replicação ViralRESUMO
Chiral nanostructures based on semiconductors exhibit pronounced properties of chiral luminescence and optoelectronic responses, which are fundamental for chiroptoelectronic devices. However, the state-of-the-art techniques of generating semiconductors with chiral configurations are poorly developed, most of which are complicated or of low yield, rendering low compatibility to the platform of optoelectronic devices. Here we show polarization-directed oriented growth of platinum oxide/sulfide nanoparticles based on optical dipole interactions and near-field-enhanced photochemical deposition. By rotating the polarization during the irradiation or employing vector beam, both three dimensional and planar chiral nanostructures can be obtained, which is extendable to cadmium sulfide. These chiral superstructures exhibit broadband optical activity with a g-factor of ~0.2 and a luminescence g-factor of ~0.5 in the visible, making them promising candidate for chiroptoelectronic devices.
RESUMO
Vectored immunoprophylaxis was first developed as a means of establishing engineered immunity to HIV using an adenoassociated viral vector expressing a broadly neutralizing antibody. We applied this concept to establish long-term prophylaxis against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in a mouse model using adenoassociated virus and lentiviral vectors expressing a high-affinity angiotensin-converting enzyme 2 (ACE2) decoy. Administration of decoy-expressing (adenoassociated virus) AAV2.retro and AAV6.2 vectors by intranasal instillation or intramuscular injection protected mice against high-titered SARS-CoV-2 infection. AAV and lentiviral vectored immunoprophylaxis was durable and was active against SARS-CoV-2 Omicron subvariants. The AAV vectors were also effective therapeutically when administered postinfection. Vectored immunoprophylaxis could be of value for immunocompromised individuals for whom vaccination is not practical and as a means to rapidly establish protection from infection. Unlike monoclonal antibody therapy, the approach is expected to remain active despite continued evolution viral variants.
Assuntos
COVID-19 , Animais , Camundongos , COVID-19/prevenção & controle , SARS-CoV-2/genética , Imunização , Imunoterapia , Vacinação , Dependovirus/genética , Glicoproteína da Espícula de Coronavírus , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/uso terapêuticoRESUMO
Rotaviruses (RVs) preferentially replicate in the small intestine and frequently cause severe diarrheal disease, and the following enteric infection generally induces variable levels of protective systemic and mucosal immune responses in humans and other animals. Rhesus rotavirus (RRV) is a simian RV that was previously used as a human RV vaccine and has been extensively studied in mice. Although RRV replicates poorly in the suckling mouse intestine, infection induces a robust and protective antibody response. The recent availability of plasmid only-based RV reverse genetics systems has enabled the generation of recombinant RVs expressing foreign proteins. However, recombinant RVs have not yet been experimentally tested as potential vaccine vectors to immunize against other gastrointestinal pathogens in vivo. This is a newly available opportunity because several live-attenuated RV vaccines are already widely administered to infants and young children worldwide. To explore the feasibility of using RV as a dual vaccine vector, we rescued replication-competent recombinant RRVs harboring bicistronic gene segment 7 that encodes the native RV nonstructural protein 3 (NSP3) protein and a human norovirus (HuNoV) VP1 protein or P domain from the predominant genotype GII.4. The rescued viruses expressed HuNoV VP1 or P protein in infected cells in vitro and elicited systemic and local antibody responses to HuNoV and RRV following oral infection of suckling mice. Serum IgG and fecal IgA from infected suckling mice bound to and neutralized both RRV and HuNoV. These findings have encouraging practical implications for the design of RV-based next-generation multivalent enteric vaccines to target HuNoV and other human enteric pathogens.
Assuntos
Norovirus , Infecções por Rotavirus , Rotavirus , Criança , Lactente , Humanos , Animais , Camundongos , Pré-Escolar , Rotavirus/genética , Anticorpos Neutralizantes , Mucosa , Anticorpos AntiviraisRESUMO
Malaria remains a devastating disease and, with current measures failing to control its transmission, there is a need for novel interventions. A family of proteins that have long been pursued as potential intervention targets are aquaporins, which are channels facilitating the movement of water and other solutes across membranes. We identify an aquaporin in malaria parasites and demonstrate that it is important for completion of Plasmodium development in the mosquito vector. Disruption of AQP2 in the human parasite Plasmodium falciparum and the rodent parasite Plasmodium berghei blocks sporozoite production inside oocysts established on mosquito midguts, greatly limiting parasite infection of salivary glands and transmission to a new host. In vivo epitope tagging of AQP2 in P. berghei, combined with immunofluorescence assays, reveals that the protein is localized in vesicle-like organelles found in the cytoplasm of gametocytes, ookinetes, and sporozoites. The number of these organelles varies between individual parasites and lifecycle stages suggesting that they are likely part of a dynamic endomembrane system. Phylogenetic analysis confirms that AQP2 is unique to malaria and closely related parasites and most closely resembles intracellular aquaporins. Structure prediction analyses identify several unusual features, including a large accessory extracellular loop and an arginine-to-phenylalanine substitution in the selectivity filter principally determining pore function, a unique feature among known aquaporins. This in conjunction with the importance of AQP2 for malaria transmission suggests that AQP2 may be a fruitful target of antimalarial interventions.
Assuntos
Aquaporina 2 , Mosquitos Vetores , Proteínas de Protozoários , Animais , Malária , Mosquitos Vetores/parasitologia , Filogenia , Plasmodium berghei/metabolismo , Proteínas de Protozoários/metabolismo , Esporozoítos/metabolismoRESUMO
Honeybees (Apis mellifera carnica) communicate the direction and distance to a food source by means of a waggle dance. We ask whether bees recruited by the dance use it only as a flying instruction, with the technical form of a polar vector, or also translate it into a location vector that enables them to set courses directed toward the food source from arbitrary locations within their familiar territory. The flights of recruits captured on exiting the hive and released at distant sites were tracked by radar. The recruits performed first a straight flight in approximately the compass direction indicated by the dance. However, this "vector" portion of their flights and the ensuing tortuous "search" portion were strongly and differentially affected by the release site. Searches were biased toward the true location of the food and away from the location specified by translating the origin for the danced polar vector to the release site. We conclude that by following the dance recruits get two messages, a polar flying instruction (bearing and range from the hive) and a location vector that enables them to approach the source from anywhere in their familiar territory. The dance communication is much richer than thought so far.